More than 900 workers across 33 businesses in the U.S. and Ireland tested a four-day workweek this year, and none of them are going back to a five-day model, according to data from one of the world's largest experiments to test the shortened workweek.

The six-month pilot, which ran for most companies from April through October, works on a 100-80-100 model: Workers receive 100% of their pay for 80% of the time and maintain 100% productivity. The initiative is led by the nonprofit 4 Day Week Global in partnership with researchers at Cambridge University, Boston College and University College Dublin.

Unsurprisingly, workers overwhelmingly enjoyed having an extra day back to themselves: They rated the experience at 9.1 on a 10-point scale, and 97% said they want to continue the condensed schedule.

Their self-reported levels of performance went up while burnout and fatigue went down. They had more control over their schedules and also saved an hour per week on commuting, even though in-person work increased throughout the trial period.

And leaders say they're willing to continue because the business didn't suffer. On average, businesses decreased their schedules by six hours, from about 41 to 35 hours per week per employee. Of those that provided data, businesses reported an 8% increase in revenue throughout the trial period, and a 38% increase from the same time period a year prior.

Jon Leland, chief strategy officer at Kickstarter, said it took a few months for the remote tech company with about 100 employees to get everyone down to a 32-hour workweek. Since figuring it out, he says, the company has seen an increase in productivity, which he believes is a direct result of workers feeling less stressed, more focused and more engaged.

It's also helped solve Kickstarter's understaffing issues this spring. Turnover has been low, job openings get a ton of applicants, and the time to hire is much faster. Both salaried and hourly Kickstarter employees are able to work a shortened week, and hourly workers got a pay raise to ensure they didn't lose earnings, Leland says.

That's not to say every business has had an easy time of the transition, or even that they were 100% successful — but so far, it doesn't look like going back to a traditional 40-hour week is on the table, either.

'Once you give people a four-day workweek, how do you take it back?'

Of the 27 companies that provided feedback at the end of the trial, 18 said they're definitely continuing the four-day workweek, seven plan to continue but haven't made a final decision, one is leaning toward continuing and one is still deciding. None are planning to discontinue the process to create more flexibility in their workweeks, according to survey data.

At Advanced RV, a motorhome manufacturer near Cleveland, Ohio, workers weren't able to fully meet the goals they'd set out for themselves in the spring: to be as productive in four days as they were in five, to maintain their customer service, and to improve the quality of their work. But company president Mike Neundorfer, who's been interested the four-day week concept for a while now, says they're trending the right direction.

He decided six months wasn't long enough to give the experiment a fair shot, and in October announced the company would extend the policy for at least another three months and reassess. It was met with "spontaneous applause," Neundorfer says.

He admits the experiment means de-prioritizing creating a return for shareholders, and focusing a little more on employee well-being.

"I've been in business for a long time and built many from scratch," he says. "If this works out, it would be the most significant thing I've done in business."

In New York City, roughly a dozen workers at Public Policy Lab can shorten their 40-hour schedules with up to eight hours of flex time throughout the week. The nonprofit doesn't necessarily advertise having a four-day schedule in their job ads — but once their weekly paid time off is mentioned in interviews, applicants want to know more, says managing director Shanti Mathew.

There's no going back, Mathew says, for the organization or for her personally: "Once you give people a four-day workweek, how do you take it back? How do you go back to working five days a week?"

Overcoming the 'theater of work'

According to 4 Day Week Global data, over one-third of surveyed employees say their workload intensified, the same share said their workload declined, and the remainder didn't see any kind of change.

Several companies said employees were hesitant to try out the experiment because they worried about doing the same amount of work in less time. That was a big concern at Advanced RV, which has roughly 50 employees. To cut down hours, they brought in new software to streamline some of their work. They also cut down on meetings and changed their format, including moving some to written communications.

Leland says Kickstarter saw some resistance from managers, since they're the ones on the hook for making changes within their team and measuring outcomes. Any kind of process change really requires managers to be focused and clear in their expectations and tests their ability to support their teams through adjustments, he says.

A lot of it comes down to overcoming the "theater of work," Leland adds.

"As work takes up more and more of our time, people are spending time at work resting or slacking off," like by surfing the internet or checking social media. "A lot of that behavior is people being burned out and trying ways to recuperate while they're working. We'd rather give people time to rest at home and come back properly focused and efficient during a shorter workweek."

Mathew agrees that rethinking what productivity looks like was also the biggest challenge.

"There's a really strong narrative of hours equaling output, and that was the biggest mental and emotional barrier," Mathew says. The experiment forced her and her colleagues to recognize that they're not equally productive every hour of a five-day, 40-hour workweek, and that they can be on the clock for less time and get the same amount of work done.

Some say you couldn't pay them to return to a 5-day workweek

According to 4 Day Week Global data, the majority of employees on the trial didn't report any feelings of job insecurity, and they didn't use their free time to take a second job.

Instead, employees used their free time on leisure, housework and personal grooming. One Advanced RV employee used a long weekend to go on a postponed trip to Scotland. At Public Policy lab, one employee regularly volunteers with an animal shelter during her off-time each week.

Workers say the extra time is worth a lot to them: 42% say they would need a 26% to 50% pay bump to go back to working Monday through Friday; 13% said you couldn't pay them enough to return to a five-day week.

A UK trial of the shortened week reached its halfway point in September and has so far yielded positive results. And as many as 40% of companies have or plan to make a four-day week the norm, according to a November survey from EY, the consulting firm.

Leland thinks the new schedule is "more profound" than a few hours off. "That's a lot of days to rest, to take ownership of different projects, to make memories with your family," he says.

It also comes down to trust between employers and employees, says Mathew. "We are handing folks more power over their schedules and over the ways they work on behalf of the organization" and with colleagues.

Her takeaway: "If you trust people, they'll prove themselves to be trustworthy."

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